Process for the interactive design of folyhedra

ABSTRACT

IN THE PROCESS DESCRIBED HEREIN, THERE IS SKETCHED ON THE SCREEN OF AN INTERACTIVE GRAPHICS DISPLAY DEVICE A FRONT VIEW AND A SIDE VIEW OF A THREE-DIMENSIONAL OBJECT SUCH AS A POLYHEDRON, A CAPACITANCE TABLET BEING A SUITABLE INPUT SKETCHING DEVICE. THEREAFTER, THERE IS DESCRIBED IN THE FRONT VIEW OF THE DEVICE, A PARTICULAR SURFACE BOUNDARY. THE TRACKING SPOT ON THE SCREEN IN PLACED OVER SUCCESSIVE VERTEX POINTS IN THE FRONT VIEW AND THE INTERACTIVE GRAPHICS DEVICE LIGHTPEN SWITCH IS CLOSED AT EVERY VERTEX POINT. THEREBY, THERE IS RECORDED FROM THE TRACKING SPOT POSITION, THE Y AND Z COORDINATES OF THE VERTEX POINT IN THE ORDER IN WHICH THESE POINTS ARE ENTERED. NEXT, THE SAME SURFACE IS DESCRIBED IN THE RIGHT SIDE VIEW BY SELECTING THE VERTEX POINTS IN THE SAME ORDER. A COMPUTER DETERMINES THE X COORDINATE IN THIS VIEW AND SINCE THE ORDER OF ENTERING DATA IS THE SAME IN BOTH VIEWS, X VALUES CAN BE ASSIGNED TO THE CORRECT VERTEX POINT. THE ORDER IN WHICH POINTS ARE ENTERED IS THE TOPOLOGICAL MAP FOR THE SURFACE AND THE COORDINATES OF ALL VERTEX POINTS ARE KNOWN. IF THE TRACKING SPOT IS DETECTED IN THE RIGHT-HALF OF THE SCREEN, ENCODED POINTS ARE TREATED IN THE RIGHT-HALF OF THE SIDE VIEW. WHEN THE NUMBER OF POINTS ENTERED FOR A PARTICULAR SURFACE ON THE RIGHT SIDE VIEW EQUAL THE NUMBER OF POINTS ENTERED FOR A PARTICULAR SURFACE ON THE FRONT VIEW, THE TOPOLOGICAL DESCRIPTION OF THE SURFACE IS COMPLETED AND AN ISOMETRIC DRAWING OF THE SURFACE IS PROJECTED. THEREAFTER, ANOTHER SURFACE IS ENCODED. IN THE COMPUTER, THERE ARE COMPARED ENCODED VERTEX POINTS TO ALL PREVIOUSLY ENTERED POINTS TO DETERMINE IF A NEW POINT IS WITHIN A SMALL ERROR DISTANCE OF ANY OTHER POINT. IF IT IS, THEN THE NEW VERTEX POINT IS TO BE REPLACED WITH THE PREVIOUSLY ENTERED POINT IN THE TOPOLOGICAL MAP. AFTER AN OBJECT IS COMPLTELY ENCODED, IN ACCORDANCE WITH THE PROCESS, THE ORTHOGRAPHIC VIEW OF THE SOLID OBJECT CAN BE RO-   TATED FOR INSPECTION. TO DETERMINE WHETHER THE SOLID IS PREFECTLY ENCODED, A HIDDEN LINE TEST CANBE MADE. IN THIS CONNECTION, OF HIDDEN LINES CAN BE ELIMINATED, THE VERTEX LIST AND THE TOPOLOGICAL MAP ARE USUALLY CORRECT AND COMPLETE. THE USE OF THE ORDER IN WHICH POINTS ARE ENTERED TO CONSTRUCT THE TOPOLOGICAL MAP AND TO ASSOCIATE COORDINATES OF POINTS BETWEEN THE FRONT AND SIDE VIEWS ENABLES COMPLETE FREEDOM IN THE TYPE OF POLYHEDRA WHICH CAN BE ENCODED AND THE TYPE OF GRAPHIC MATERIAL BEING TRACED. THE PROCESS CAN, THEREFORE, BE EMPLOYED TO CALCULATE COORDINATES AND THE TEDIOUS WORK OF WRITING DOWN THE VERTEX LIST AND THE TOPOLOGICAL MAP IS ELIMINATED. THE PROCESS IS PARTICULARLY APPLICABLE IN NUMERICAL CONTROL TECHNIQUES.

DEFENSIVE PUBLICATION UNITED STATES PATENT AND TRADEMARK OFFICE Published at the request of the applicant or-owner in accordance with the Notice of Dec. 16, 1969, 869 O.G 687. The abstracts of Defensive Publication applications are identified by distinctly numbered series and are arranged chronologically. The heading of each abstract indicates the number of pages of specification, including claims and sheets of drawings contained in the application as originally filed. The files of these applications are available to the public for inspection and reproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to the merits of allemed invention. The Patent and Trademark Office makes no assertion as to the novelty of the disclosed subicct matter.

PUBLISHED JUNE 3, 1975 935 O.G. 1O

T935,004 .l- PROCESS FOR THE INTERAC IIVE DESIGN I 0F POLYHEDRA Arthur Appel, 1512 Indiana Ave., Yorktown Heights,

NY. 10598, Arthur J. Stein, 35 Wheeler Drive, Peeknouns-1s DETECTED no skill, N.Y. 10566 Continuation of abandoned application Ser. No. 318,452, 1 H c 0 5 Dec. 26, 1972. This application May 17, 1974, Ser. No. WES TNG T R 471,090

Int. Cl. G061? 15/20 m 444-1 rsnurr EtUATIONS 38 Sheets Drawing. 82 Pages Specification or muss no user 750 vuusx POINT READ 09F communes INITIALIZE com E 2 r guuo giglsuu, ggf S msnu u; 1r-

' "cm" 5 CARD "TABLET" 1S DETECTED MATH MATICALLI CORRECT 5m) [5 DETEND /774 ls win is DETECTED 1F 51mm FACTORS MAKE OBJECT ARE READ IN SYMMETRH) AuourA nun VERTEX usr VERTEX PW ms LEAST HAY PLANE- FROM suns. QEP P SQUARE scrum READ roPoLoucAL MAP 154 H "SYMY" IS aurora) us FROM CARDS. REQORMNG TABLET PEN WEIFHIING FACTORS.

STATE no cooanmurs mm "rarest m with 145th? liii'lti 955i. on NORMAL SURFACES.

SAVE or cums nuns 'SOUD" 0R m mg "PUNCH 1s aurora u DETECTED I IS DETECTED CURRENT pm, PUNCH 0N CARDS 0R FILE CALCULATE rouuluus or ALL sunmrs in ms AVERAGES l cunnu vzmsx Llsr 0F ALL vuurx POINTS READ m" CARDS no TOPULOGICAL no.

ne or FILE ovum om. I 764 the tracking spot is detected in the right-half of the screen, encoded points are treated as being in the right side view. When the number of points entered for a par- [750 ee ticular surface on the right side view equal the number msnu AUSER DISPLAY, mm of points entered for a particular surface on the front X OONT'NUMLY CONHNUALLY view, the topological description of that surface is comg l fi Q Q I Q pleted and an isometric drawing of that surface is proteins LABELLED, "wmr FRAMEMUDE HIDDEN Lur'uonr ected. Thereafter, another surface is encoded. In the In the process described herein, there is sketched on the screen of an interactive graphics display device a front view and a side view of a three-dimensional object such as a polyhedron, a capacitance tablet being a suitable input sketching device. Thereafter, there is described in the front view of the device, a particular surface boundary. The tracking spot on the screen is placed over successive vertex points in the front view and the interactive graphics device lightpen switch is closed at every vertex point. Thereby, there is recorded from the tracking spot position, the Y and Z coordinates of the vertex point in the order in which these points are entered. Next, the same surface is described in the right side view by selecting the vertex points in the same order. A computer determines the X coordinate in this view and since the order of entering data is the same in both views, X values can be assigned to the correct vertex point. The order in which points are entered is the topological map for the surface and the coordinates of all vertex points are known. If

computer, there are compared encoded vertex points to all previously entered points to determine if a new point is Within a small error distance of any other point. If it is, then the new vertex point is to be replaced with the previously entered point in the topological map. After an object is completely encoded, in accordance with the process, the orthographic view of the solid object can be rotated for inspection. To determine whether the solid is perfectly encoded, a hidden line test can be made. In this connection, if hidden lines can be eliminated, the vertex list and the topological map are usually correct and complete. The use of the order in which points are entered to construct the topological map and to associate coordinates of points between the front and side views enables complete freedom in the type of polyhedra which can be encoded and the type of graphic material being traced. The process can, therefore, be employed to calculate coordinates and the tedious work of writing down the vertex list and the topological map is eliminated. The process is particularly applicable in numerical control techniques.

ISSUE OF AUGUST 19, 1975 UNDER PAT., T.M. & SEPARATES NOTICES k ERRATA In the notices of Defensive Publications appearingon pages 912 in the Official Gazette of June 3, 1975, the names of the assignees were omitted and should be added as indicated below:

T935,001. E. 1. du Pont de Nemours and Company, Wilmington, Del. T935,002. Pacific Lighting Service (30., Los Angeles, Calif.

T935,003. International Business Machines Corporation, Armonk, N.Y. T935004. International Business Machines Corporation, Armonk, N.Y. T935,005. International Business Machines Corporation, Armonk, N.Y. T935,006. I I. du Pont de Nemours and Company, Wilmington, Del.

In the notices of Defensive Publications appearing on pages 7 and 8 in the Ofl'icial Gazette of July 1, 1975, the following names of assignees were omitted and should be added:

T936,001. E. L du Pont de Nemours and Company, Wilmington, Del. T936,002. E. I. du Pont de Nemours and Company, Wilmington, Del. T936,005. DuPont of Canada Limited, Quebec, Canada A. A'PPEL ETAL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972 FIG. IA

June 3, 1975 58 Shane- Sheet 1 June 3, 1975 A APPEL ET AL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972 58 Sheets-Sheet a FIG. 1B

June 3, 1975 A.APPEL ET AL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26. 1972 58 Sheets-Sheet 3 FIG. 1C

June 3, 1975 A. APPEL ET AL T 935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972. 58 Sheets-Sheet 4 FIG. 2 FIG. 3

A IWEPOQ FRONTVIEW RIGHT SIDE VIEW FRONTVIEW TRACKING RIGHT SIDE SPOT VIEW FIG. 4 H6, 5

I A I I FRONTVIEW RIGHT SIDE TRACKING FRONTVIEW RIGHTSIDE \TRACKINC VIEW SPOT VIEW SPOT TRACKING TRACKING FIG. 6 Sim FIG. 7 5 0T I I IF I I EDI I i I I I VIEWS ON INTERACTIVE GRAPHICS VIEWS ON INTERACTIVE GRAPHICS DEVICE 0R TABLET DEVICE 0R TABLET June 3, 1975 A. APPEL ET AL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972 5a Sheets-Sheet 5 June 3, 1975 A. APPEL ET AL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972 58 Sheets-Sheet 6 INTERACTIVE DISPLAY UNIT ISOMETRIC 10 WIRE FRAME IMAGE IT 12 CONTRITEEER [LIGHT], KEY5\ PEN 14 SET ORIGIN CANCEL END OBJECT I CARD WIRE SCALE 1.0000 SOLID RESTART \i fi IIIIII. \L I DRAWINGS 0F OBJECT TO BE ENCODED IN THREE DIMENSIONS June 3, 1975 A. APPEL ET AL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26. 1972 38 Sheets-Sheet 7 IOVEREI DETER MINED URF C SURFACE 2 S A E) (OVERLY DETERMINED SURFACE I SURFACE) (OVERLY DETERMINED SURFACE) (EXACTLY DETERMINED SURFACE) SURFACE 5 (EXACTLY DETERMINED POINT 2 POINT) (OVERLY DETERMINED POINT) FIG. 15

FIG. 16

AVERAGE VERTEX POINT WITH COORDINATES (PAX,PAY,PAZ)

June 3, 1975 A.APPEL ETAL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26. 1972 58 Sheets-Sheet 8 START j g: FIG. 3A 7 FIG. 13

20 INITIALIZE DISPLAY FIG.

F"! 22 JCARD-*2 DISPLAY LIGHTKEYS II II 1| 1| CARD AND TABLET 23 0N SCREEN 26\ TEST FOR LIGHTKEY INTERRUPT DETECT /DETECT TABLET '1 "CARD" 28\ REMOVE LIGHTKEYS FROM DISPLAY READ FROM CARD AM, IHD

FROM 262 F|G.13L

52 READ KK,X(KK),Y(KK),Z(KK) NK- KK -55 34 lSKK- -999? YES NO June 3, 1975 A. APPEL ET AL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972 58 Sheets-Sheet 10 F|G.I3C

I II

CALCULATE THE AVERAGE FROM 208 FIG. I3 J 60 VALUES OF THE VERTEX POINT COORDINATES FROM I42 FIG. 13G

CALCULATE THE EQUATION 66 OF THE PLANE I USING THE FIRST THREE POINTS LISTED AS BEING ON THAT PLANE V I CALCULATE THE DISTANCE 68 OF AVERAGE VERTEX POINT FROM PLANEI FIND COORDINATES OF THE 70 PROJECTION OF AVERAGE VERTEX POINT ONTO PLANE I IS I NS YES NO June 3, 1975 A. APPEL ET AL Original Filed Dec. 26, 1972 58 shgets shaet 11 PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA FIG, 13D

F We- KK K +1 76 9 9 +2 q CALCULATE DIRECTION 78 CO3 l NES FOR ORTHOCRAPHIC PROJECT ION CALCULATE DISTANCE FROM 80 AVERAGE VERTEX POINT TO PICTURE PLANE V CALCULATE AND STORE 86 ORTHOCRAPH IC PROJECTION OF EACH VERTEX POINT 88 IS I N K YES NO REMOVE CURRENT DISPLAY OF OBJECT June 3, 1975 Original Filed Dec. 26, 1972 A. APPEL ET AL PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA 38 Sheets-Sheet 12 June 3, 1975 A. APPEL ET AL PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972 IS J LL YES N0 IS I NS 58 Sheets-Sheet 15 YES NO LS KKK KMAX YES m Nol YES REMOVE LIGHT KEYS FROM DISPLAY DISPLAY ON SCREEN LIGHT KEYS FIG.13F

June 3 1975 A, APPEL ET AL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972 58 Sheets-Sheet 14 FIG.13G

INITIALIZE PARAMETERS 152 READ CURRENT POSITION OF TABLET PEN (IX,IY,IZ)

DRAW DOT ON SCREEN N156 CORRESPONDING TO IX,IY

IS IZ=T'? YES NO 140\ V I3 ISYJ O NO YES "WHO" IS DETECTED, GO TO 550(F|C.15N)

- "CARD" IS DETECTED,CO TO 262(FIG.15L)

- "RESTART" IS DETECTED,CO TO 20(FIG.15A)

"SAVE" IS DETECTED,GO TO 2T2(F|G.15L)

- -"CANCEL" IS DETECTED, GO TO 264(F|G.13L)

"FLAT" IS DETECTED, GO TO 384(F|G.13Q)

"SOL|D" IS DETECTED,GO TO 60(FIG.15C)

- "END OBJECT" IS DETECTED,GO TO 236(F|C.13K)

-"WIRE IS DETECTED,GO TO 208(F|G.13J)

+"SCALE" IS DETECTED,CO TO 206(FIG.15J)

- "ORIC|N" IS DETECTED,GO TO 204(FIG.13J)

IS IVF =1 446 NO YES NPX June 3, 1975 A. APPEL m1; T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26. 1972 se Sheets-Sheet 15 1;; 0 13 H 11vF-- 11v F- 1 /152 1 1s IOR=0 /158 ICY IX 15 111R :1 M60 110 [YES I 1s 1x 512 162 110 IYES IVF 1 1185 June 3, 1975 A. APPEL, ET AL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec. 26, 1972 58 Sheets-Sheet 17 I. 'W- -fi SET BLANK BEAM \1192 IS GRAV GMIN /226 DX(KE),DY(KE) YES NO NPX--I /228 ILD -0 195 ILD-ILD+1 N194 NKG-LS(NS)-NVF 252 KE .K(NSIILD) #196 K(NS,NKG)NPX DRAW LINE TO 4198 DX(KE), DY(KE) 254- IS I=NP1? YES NO ILD=NLD 200 NO YES FIG. i3d

READ FROM CARD NEW 206 VALUE OF SCALE T0 60 FIG. I50

June 3 1975 A, APPEL ETAL T935,004

PROCESS FOR THE INTERACTIVE DESIGN OF POLYHEDRA Original Filed Dec, 26, 1972 58 Sheets-Sheet 18 FROM 142 FIG. 15G

FIG. 13K

Ns-Ns-1 /256 IQ O -/240 IS NK KE? /254 NO YES I0 I0+i /242 NK KE M256 REMOVE SURFACE 244 15 10 LSO M58 IQ FROM SCREEN NO YES 260- |sI0 Ns? Lso LS (I0) 146 NO YES 

